Shared Noise Filter for Compact Switching Power Supply

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Solution Overview

Problem

Existing power supply devices with multiple switching power supplies face increased loss and circuit size due to the use of multiple filters, which are necessary to address switching noise but result in inefficiencies and bulkiness.

Innovation Solution

A power supply device configuration featuring first and second switching power supplies, a noise filter, and a shield, where the noise filter is strategically placed between the switching power supplies and the power storage device, and shared across multiple current paths to minimize the number of filters and reduce electromagnetic noise, thereby restricting loss and circuit size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If multiple noise filters are provided for each switching power supply, then switching noise is effectively reduced, but power loss increases and circuit size increases

Engineering Contradiction:
Improveswitching noiseVSAvoidpower loss
Core Design Contradiction:
Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent combines multiple noise filters into a single shared filter unit that serves multiple switching power supplies. Instead of providing separate filters for each power supply, one filter is strategically positioned to handle noise from all supplies, reducing the total number of filters and associated power losses while maintaining noise suppression effectiveness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The noise filter is designed with universal functionality to serve multiple switching power supplies simultaneously. By positioning the filter on a common current path that carries noise from all power supplies, it performs the noise reduction function for the entire system rather than requiring dedicated filters for each individual supply.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If multiple noise filters are provided for each switching power supply, then switching noise is effectively reduced, but circuit size increases

Engineering Contradiction:
Improveswitching noiseVSAvoidcircuit size
Core Design Contradiction:
Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The patent merges multiple separate filter circuits into a single integrated filter unit. This consolidation dramatically reduces the total volume occupied by filtering components, as one shared filter replaces what would otherwise be multiple discrete filters, each requiring its own space in the circuit layout.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The filter is designed as a universal component that handles noise from multiple power supplies through a shared current path. This multi-functional approach eliminates the need for separate filter circuits for each power supply, thereby reducing overall circuit size and component count while maintaining comprehensive noise suppression.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If a noise filter is provided on each current path, then noise is reduced, but the number of components increases

Engineering Contradiction:
Improveelectromagnetic noiseVSAvoidnumber of components
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the noise filtering function across multiple current paths into a single filter component. By positioning one filter on a common path that intersects or shares segments with multiple power supply current paths, the design achieves comprehensive noise filtering without requiring separate filters for each path, thus reducing component count and simplifying the overall device structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The filter is designed with universal applicability to multiple current paths. A single filter unit serves multiple switching power supplies by being positioned on a shared or intersecting current path, allowing it to suppress electromagnetic noise from all supplies simultaneously. This approach maintains effective noise reduction while minimizing the number of components required.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration minimizes the number of filters required, reducing power loss and circuit size while effectively addressing switching noise, resulting in a more efficient and compact power supply device.

Implementation Method 1

a shield that covers the first and second switching power supplies and the noise filter, and blocks electromagnetic noise

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 2

a filter for removing the switching noise is provided in a power supply device

Methodology Applied
Scientific EffectElectromagnetic filtering: Filter (electronic)

Data Source

PatentEP3171500B1Power supply device
Publication Date: 2020.10.14 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3171500B1 patent drawingFigure 1
  • EP3171500B1 patent drawingFigure 2
  • EP3171500B1 patent drawingFigure 3

AI summary

A power supply device includes a first switching power supply that converts power of input power supply and supplies the converted power to a power storage device, a second switching power supply that converts power supplied from the first switching power supply or the power storage device and supplies the converted power to a load device, a noise filter that reduces noise generated in the first and second switching power supplies, and a shield that covers the first and second switching power supplies and the noise filter, and blocks electromagnetic noise. The noise filter is provided between the first switching power supply and the power storage device, between the power storage device and the second switching power supply, and nearer to the power storage device than a branch point at which a power line from the first switching power supply to the power storage device intersects a power line from the second switching power supply to the power storage device.